There are known in the art, for example from EP-A-0561444, machines for the formation of tablets of cosmetic product. Said machines comprise feeding means (for example feeding hoppers) of a cosmetic product in powder to a conveyor belt to determine the formation of a levelled layer of cosmetic product that is moved by said conveyor belt. The tablets are formed by portioning the levelled layer of cosmetic product by means of hollow punches movable vertically that, from a raised position, are lowered so as to immerse them in the layer of cosmetic product; pressure pistons slidable inside the hollow punches then compress the portion of cosmetic product contained in the hollow punch itself against the conveyor belt, and the hollow punches, containing the tablet of cosmetic product, are then raised again and moved to an area of deposition of the tablets of cosmetic product in special containers.
In such machines, downstream from the feeding hopper there are levelling means of the layer of cosmetic product that allow a layer of product levelled to a pre-set height to be obtained; said levelling means consist substantially of a static divider panel placed at a pre-set distance from the conveyor belt corresponding to the desired thickness of the layer of cosmetic product. The speed at which the conveyor belt moves is determined so that, in relation to the rate of delivery of the feeding hopper, there is formed under the hopper itself a layer of cosmetic product that is not levelled and whose thickness is greater than that of the levelled layer of cosmetic product.
The thickness of the levelled layer is determined solely by the distance of the fixed divider panel from the conveyor belt. In order to vary the thickness of the levelled layer it is necessary to vary the distance of the fixed divider panel from the conveyor belt. Moreover, the use of the fixed divider panel to level the layer of cosmetic product gives rise to irregularities caused by the fact that the cosmetic product adheres to the fixed divider panel altering its profile.